This is a maintenance release. The following items were fixed and/or added:
Virtualization core: support Shanghai/Zhaoxin CPUs.
User interface: handle command line arguments to VirtualBox correctly (bugs #18206 and #18197)
User interface: improvements to machine manager window, virtual optical disk creator, storage selector window and log viewer window
User interface: various small fixes and improvements
Audio: implemented time scheduling for the AC'97 device emulation to keep audio and video in sync
Graphics: basic support for VMSVGA graphics device in virtual machines using EFI
Network: fix occasional NATNet crashes (bug #13899)
Network: worked around problems in certain PCnet drivers on old operating systems
Serial: fixed connecting to pseudo terminals on POSIX hosts (6.0.0 regression; bug #18319)
Linux hosts and guests: fix for building kernel modules against Linux 5.0. Thank you Kyle Laker